Andreas Christian

Europa-Universität Flensburg · Biology

This article studies the differences between first-time and repeat visitors to a large temporary exhibition at a natural history museum. Cued visitors were overtly observed and then interviewed. Compared to first-time visitors, repeat visitors generally visited museums more frequently and tended to be more interested in science. During the visit, t...

Participant reactivity was examined in a section of the National Park Center Multimar Wattforum in Tönning, Germany, which combines aquariums with exhibits typical of museums and science centers. Engagement times with exhibits were compared between cued and uncued visitors. Cued visitors were overtly observed. Some were also prompted before the obs...

A very long neck is a characteristic feature of most sauropod dinosaurs. In the genus Mamenchisaurus, neck length is extreme, greater than 40 percent of total body length. However, the posture, utilization, and selective advantage of very long necks in sauropods are still controversial. An excellently preserved skeleton of Mamenchisaurus youngi, in...

The histology of cervical ribs of Sauropoda reveals a primary bone tissue, which largely consists of longitudinally oriented mineralized collagen fibres, essentially the same tissue as found in ossified tendons. The absence of regular periosteal bone and the dominance of longitudinal fibres contradict the ventral bracing hypothesis (VBH) postulated...

The herbivorous sauropod dinosaurs of the Jurassic and Cretaceous periods were the largest terrestrial animals ever, surpassing the largest herbivorous mammals by an order of magnitude in body mass. Several evolutionary lineages among Sauropoda produced giants with body masses in excess of 50 metric tonnes by conservative estimates. With body mass...

A very long neck that is apparently suitable for feeding at great heights is a characteristic feature of most sauropod dinosaurs. Yet, it remains controversial whether any sauropods actually raised their necks high. Recently, strong physiological arguments have been put forward against the idea of high-browsing sauropods, because of the very high b...

pdf

neck flexibility of recent animals. sauropod neck

In light of evidence for avian-like lungs in saurischian dinosaurs, the physiological implications of cross-current gas exchange and voluminous, highly heterogeneous lungs for sauropod gigantism are critically examined. At 12 ton the predicted body temperature and metabolic rate of a growing sauropod would be similar to that of a bird scaled to the...

In their perspective “Sauropod gigantism” (10 October 2008, [p. 200][1]), P. M. Sander and M. Clauss assumed that in order to meet their high energy demands, these long-necked dinosaurs browsed in tall trees, as do today's giraffes. Recent museum reconstructions of Barosaurus and Brachiosaurus

Compressive forces acting on the intervertebral discs along the neck of Brachiosaurus brancai from the Late Jurassic of Tendaguru are calculated for different neck postures. The distribution of compressive forces along the neck is compared to the distribution of the cross-sectional areas of the intervertebral discs. Neck postures in which the patte...

The gross morphology and the flexibility along the neck of the ostrich (Struthio camelus) were examined using fresh tissue as well as neck skeletons. The results of the morphologic studies were compared with results from observations of living ostriches. The investigation was focused on differences in the morphology and the function between differe...

The neck posture of Brachiosaurus brancai Janensch, 1914 is reanalysed by employing the Preuschoft method to deduce the pattern of stress in the joints between the vertebral centra along the neck. The cogency of different methods for reconstructing the posture of a long neck, especially the Preuschoft method and approaches that are based on optimal...

The neck posture of Brachiosaurus brancai Janensch, 1914 is reanalysed by employing the Preuschoft method to deduce the pattern of stress in the joints between the vertebral centra along the neck. The cogency of different methods for reconstructing the posture of a long neck, especially the Preuschoft method and approaches that are based on optimal...

The article presents the results of a study of the cause of horn damage in five black rhinos (Diceros bicornis) at the Magdeburg zoo in Germany. The goal was to determine whether malnutrition, stereotypical horn rubbing, rubbing on unsuitable material, moist horns or the conditions of the rhinos' keeping may be the cause of the horn damage. Malnutr...

The stress on the intervertebral discs in the necks of Brachiosaurus brancai, Diplodocus carnegii, and Dicraeosaurus hansemanni are calculated for various hypothetical neck postures. Assuming similar safety factors along the neck and a predominance of static or quasistatic forces, neck postures in which the stress is not more or less constant along...

To develop a protocol for CT examinations of fossilized saurian bones and to provide paleontologists with morphometric and densitometric data suitable for functional analysis, four isolated long bones of Tendaguru dinosaurs from the Museum for Natural Sciences of the Humboldt University of Berlin were examined by CT. The demonstration of fossils in...

The stress on the intervertebral discs in the necks of Brachiosaurus brancai, Diplodocus carnegii, and Dicraeosaurus hansemanni are calculated for various hypothetical neck postures. Assuming similar safety factors along the neck and a predominance of static or quasistatic forces, neck postures in which the stress is not more or less constant along...

Speeds of walking dinosaurs that left fossil trackways have been estimated using the stride length times natural pendulum frequency of the limbs. In a detailed analysis of limb movements in walking Asian elephants and giraffes, however, distinct differences between actual limb movements and the predicted limb movements using only gravity as driving...

The posture and mechanics of the forelimbs of Brachiosaurus brancai were analysed with the help of biomechanical models. Peak forces in the joints due to acceleration of the fraction of body weight carried on the shoulder joints are critical in models with completely straight, column-like limbs and a rigid shoulder girdle. During fast walking, eith...

10-19-1999, Forelimbs, posture and mechanics of Brachiosaurus

The mode of locomotion of Leptictidium has been discussed controversially. While some authors regard Leptictidium as a bipedal hopper, others favour the idea of bipedally running with alternately moving hindlimbs in this genus. From a biomechanical analysis some fundamental differences between the constructions of bipedally hopping and bipedally ru...

Speeds of walking dinosaurs that left fossil trackways have been estimated using the stride length times natural pendulum frequency of the limbs. In a detailed analysis of limb movements in walking Asian elephants and giraffes, however, distinct differences between actual limb movements and the predicted limb movements using only gravity as driving...

The posture and mechanics of the forelimbs of Brachiosaurus brancai were analysed with the help of biomechanical models. Peak forces in the joints due to acceleration of the fraction of body weight carried on the shoulder joints are critical in models with completely straight, column-like limbs and a rigid shoulder girdle. During fast walking, eith...

The mechanical requirements for arboreal life are reviewed and the constraints which these requirements impose on the body of a prosimian are defined. The mechanical necessities can be fulfilled only by animals which possess the appropriate morphological characters. It is incorrect to refer to these morphological traits directly as 'adaptations'. I...

Simple measurements were taken from the vertebral column of several extinct and extant terrestrial vertebrates in order to estimate the bending moments in a sagittal plane that could be sustained along the longitudinal body axis. According to theoretical expectations, the estimated patterns of sustainable bending moment prove to differ between bipe...

The pelvis ofPlateosaurus is examined from a biomechanical point of view. The shape of the acetabulum in particular is analysed in order to determine the range of possible directions of the forces exchanged between femur and pelvis. These forces must have been more or less confined to a sagittal plane. From a quasi-static analysis under considerati...

The lengths and diameters of the limb segments of 105 monitor lizards from 22 species were measured on preserved museum specimens in order to determine whether limb proportions vary in relation to snout-vent length (used as an indicator of overall body size). Scaling exponents (slopes of allometric equations) were estimated for log-transformed spec...

The mechanical laws which make possible several characteristic and well-known modes of primate locomotion are reviewed. Biological requirements are fulfilled in small and in large primates by utilizing different mechanical principles. On the basis of the mechanics, special morphological traits can be identified which are advantageous for performing...

Bipedal locomotion can be observed in numerous species of recent tetrapodal reptiles which usually have well developed tails and hindlimbs while the forelimbs are considerably shorter and weaker than the hindlimbs. It is commonly used when the reptiles move at the highest possible speeds of locomotion. The different development of the extremities i...

The self-splicing rRNA intron of Tetrahymena thermophila belongs to a subgroup of group I introns that contain a conserved extra stem-loop structure termed P5abc. A Tetrahymena mutant precursor RNA lacking this P5abc is splicing-defective under standard conditions (5 mM MgCl2/200 mM NH4Cl, pH 7.5) in vitro. However, the mutant precursor RNA by itse...

Pulsed nuclear magnetic resonance proved to be a complementary new technique for the study of moving dislocations in b.c.c. metals. From the motion induced part of the spin-lattice relaxation rate the mean jump distance of mobile dislocations has been measured in Vanadium as a function of temperature. The NMR experiments are combined with transmiss...